Clamp-on rod holder



FIG. 1 is a top perspective view of a clamp-on rod holder showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a right side elevational view thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom plan view thereof.

The broken line showing of a rod illustrates environment only and forms no part of the claimed design. 

The ornamental design for a clamp-on rod holder, as shown and described. 